This invention relates in general to cutting devices and in particular to a new and useful device for cutting workpieces with a laser beam and to means for cooling the workpiece during the cutting.
The invention relates to a method and device for cutting workpieces, particularly metal sheets, by means of a laser beam. Such cutting is known per se. The "surface of cut" is particularly neat and is obtained at a relatively high speed. In a way similar to other methods of cutting by burning through, which, however, do not result in such a satisfactory edge or surface of cut and leave a relatively wide track, the material is locally heated up so intensely that it evaporates. The heat dissipates into the neighboring areas of the workpiece, so that a gradual cooling takes place. This heat dissipation does not raise problems if straight or moderately curved paths are followed. However, a larger area becomes heated if a sharply curved portion or even an acute angle is to be cut. The reason is that within a certain relatively narrow zone, heat accumulates since it is transmitted from both sides but cannot dissipate quick enough in the opposite direction. Further, while negotiating a sharp curve or an angle, the speed of the tool relative to the concerned area is necessarily reduced. The insufficient heat dissipation results in a reduced quality of the edge of cut.